Hair drug testing: Many street drugs (or their breakdown products in the body) are absorbed into the hair. A sample of hair can be tested for recent drug use. Hair analysis: Testing of hair for toxic exposures, such as lead or mercury poisoning.
Gas Water Heater, water not hot enough-Thermostat or Sediment. The dip tube probably disintigrated. The dip tub sends cold water to the bottom of the tank for heating when its heated it rises to the top of the tank. Its possible that the dip tube broke of and now you have cold water mixing with the hot water on top.
If there's no leak, an overheat is caused by a problem with coolant level, coolant circulation, or heat transfer. Fill the coolant level. If the problem recurs within a month, it was something other than low level. Circulation problems are caused by clogged radiators, bad water pumps, non-functioning thermostats.